Appearance and comfort
The Ultrahuman Air is smooth on the outside, with no shaping or indentations. The unit I reviewed is in Bionic Gold (which costs the same as the more basic colors). Ultrahuman suggests wearing it on your index, middle, or ring finger, and I chose a size to fit my index finger.
Just inside the gold exterior is a thick layer of clear material, thick enough I can see a bit of refracted daylight when I look down at my finger while I’m typing. Comparing it to Oura, I’d say the Ultrahuman is slightly thinner and sleeker than the gen 3, but not quite as thin as the gen 4. The Ultrahuman ring also has a flattened area at the base, on the interior—no sensor bumps, but the interior is not completely round, either.
Overall I found it comfortable to wear when sleeping and for everyday use. I didn’t find it practical to wear when lifting weights (but I take all my rings off to lift, anyway). The gold material doesn’t have any noticeable scratches after a few months of wear, which is a plus.
Sizing
You need to know your size before you buy the Ultrahuman ring, and the way to do that is to order a sizing kit. You can buy the kit for under $US1 from Amazon, or place your order for the ring from Ultrahuman and add on the free sizing kit that they’ll send you before shipping the actual ring.
The sizes run from 5 to 14, whole sizes only. I liked that the sizing kit also includes mockups of the five finishes: raw titanium, aster black, matte grey, space silver, and bionic gold. (My kit didn’t mention the brushed rose gold, which is a newer color.)
As far as I can tell, the sizing rings are a good match for the actual ring; I got a size 8 and it seems to fit the same.
Charging and battery life
The Ultrahuman ring should last four to six days on a charge, Ultrahuman says, but that depends how you use it. There are different battery usage modes, with Chill Mode giving you an extra 35% of time before you need to charge. It saves battery by sampling data less often while you’re awake. Turbo Mode, meanwhile, “runs all sensors at full intensity” throughout the day. There is also a Critical Battery Mode that cuts off even more functionality to preserve battery life.
I used the ring in Chill Mode, and found that it took about four days to drain from 100% to 25%, suggesting a battery life of five to six days in that mode. This is less than I get from the Oura ring (five to seven days, in my experience), and less than a Whoop or a Garmin smartwatch (which tend to last a week or two). Ultrahuman correctly points out that it has a longer battery life than most smartwatches, like the Apple Watch or Samsung Galaxy Watch, which tend to only last a day or two.
The Ultrahuman ring also disappointed me with how long it takes to charge—two to three hours, in my experience. (Ultrahuman says to expect two hours for charge time.) Sometimes I’d put my Oura and Ultrahuman rings on to charge at the same time. When I’d pick them back up, the Oura would be fully charged and the Ultrahuman wasn’t even close.
Between the slow charging and the slightly shorter than expected battery life, I found myself running out of battery if I wasn’t paying close attention. You’ll get a notification when you’re at about 30% battery, but as you’ll see, I ended up having to turn my notifications off because the ring was pestering me about so many things so often. Since one of the best things about smart rings is that you can pretty much ignore them as you go about your life, this is a minus for me.
Sleep and health tracking
The Ultrahuman app has a sci-fi vibe to it, so you feel more like you’re piloting a high-maintenance mech than simply existing in an already basically functional human body.
For example, this morning the app thinks I got a good amount of REM sleep, so my sleep card says “Emotional processing: Complete.” My sleep score of 82 (a made-up number, as all sleep scores are) is tagged “meteoric rise” since I had a lower score yesterday. The app believes I got three full sleep cycles last night, which earns me a green checkmark.
Scrolling down the page, I can see that I have a sleep debt of 11 minutes, which comes with a suggested bedtime. I also see a ticking clock—counting down by seconds even though I have more than 10 hours left—telling me what phase of the day I am in. Right now, it’s the “circadian dead zone,” when light and activity have no special effect. (Early morning and late evening are the non-dead times).
There’s a lot of stuff on the main screen of the app, not much of which is actually valuable. (I’ll say more below about why I think the coolest-looking parts are the least useful.) If you just want a sense of “how did I sleep?” or “how is my body responding to stress?” you have to filter through all of the minutiae to find it.
That said, if you just want the basic numbers—sleep duration, resting heart rate, and HRV are the most useful, in my opinion—the Ultrahuman ring captures them fine.
Why I’m not impressed by the biohack-y data analysis
The data continues like this, in a way that I find both overwhelming and overconfident. Remember, no consumer wearable actually tracks sleep stages accurately. So to say that I got a certain amount of REM sleep is already a leap, but one that all smart devices do these days, so we’re kind of used to it. Counting my sleep cycles is another leap. Extrapolating to “emotional processing” and declaring that “complete” are yet further leaps.
Or to take another example, I get a “brain waste clearance” score every morning. (Today it’s 79.) This is based on my amount of deep sleep, total sleep, and various scores the app has calculated. While it’s true that many scientists believe that our brain clears waste during sleep, this process is still in the very beginning stages of being understood, with scientists still puzzling over the results of studies done in mice. The science certainly does not back up a matter-of-fact brain waste clearance score, even if you could figure out what to do with that number.
The caffeine window is probably one of the cutest, catchiest features on the app, and it’s based on a myth that biohacker types have fully bought into. The idea is that you should avoid caffeine in the early morning to better “optimize” how caffeine works for you. Unfortunately, it’s not true. There’s nothing about early morning caffeine that would impair your brain function or desensitize you to the effects of caffeine later in the day. In fact, there’s a lot to be said for getting your caffeine in early, so that your body can be sure to process it long before bedtime. I have a more in-depth explanation of this myth here, including a breakdown of exactly why scientists disagree with the biohacking influencers.
The Ultrahuman app is full of this kind of thing. Data points aren’t presented straightforwardly; everything has a supposed meaning, even if the science isn’t there to back one up.
Some of these are potentially useful, like sleep debt or social jet lag. Minimize those numbers, and you’ll find yourself on a more consistent sleep schedule. But many are either distractions (why would your brain waste score even matter?) or send you down an unnecessary path.
For an example of that last one, I turned on the Vitamin D power plug, which tracks things like sun exposure, and was always being told I wasn’t getting enough Vitamin D. Coincidentally I got my Vitamin D tested, and it was fine. Don’t trust this app to interpret your life.
“Power plugs” and premium features
Ultrahuman makes a big deal of being subscription-free, but that really only refers to the main functions of the ring. They’re correct that this is a big plus compared to Oura: With Oura, you need to pay monthly to get any use out of the ring at all. With Ultrahuman, the basic data shows up without an extra charge.
But it’s not subscription-free. There are certainly subscriptions you can pay for through the Ultrahuman app. For $US2.90/month you can get the Cardio Adaptability feature. For $US4.90/month, coming soon, you can get Afib Detection. If you drive a Tesla, you can pay $US6.90/month for UltraSync for Tesla, which gives you a Drive Readiness Score. And there is a $US3.99 “Pro” version of Cycle & Ovulation that says it can confirm ovulation with 90% accuracy, and tell you when you didn’t ovulate. The Cycle & Ovulation Pro and the Cardio Adaptability subscription fees are HSA/FSA eligible, the app says.
Many power plugs are free, though. Social Jetlag is a cute idea, pointing out when your sleep schedule is out of sync. Cycle & Ovulation gives you menstrual and fertility tracking functions. There is a separate power plug for Pregnancy Insights, and a New Parent power plug that says it adapts your recovery score to account for the irregular sleep a lot of new parents have to deal with.